Modern mobile devices (as well as battery powered devices) should be characterized by high performance but are expected to consume few power as possible.
Such devices include multiple semiconductor circuits. A power consumption of a semiconductor circuit includes leakage power consumption and switching power consumption. Leakage power consumption is attributed to leakage currents that flow through semiconductors components (such as transistors, diodes, and the like) of the semiconductor circuit while switching power consumption is attributed to switching activities of these semiconductor components.
Many power reduction techniques were developed during the last decades. Techniques such as differential voltage and frequency scaling (DVFS) and power gating are aimed to reduce the switching power consumption. DVFS involves altering the supply voltage level and clock signal frequency provided to a circuit. Power gating includes operating a semiconductor circuit at a maximal frequency and a maximal supply voltage level during activation periods and shutting down the circuit during deactivation periods. SRPG involves saving the state of some flip flops of the semiconductor circuit even when the circuit semiconductor is shut down.
Other techniques such as well-biasing are aimed to reduce leakage power consumption. Low leakage manufacturing processes also exist but yield in slower semiconductor circuits.